Mineral oil containing resinified esters of salicylic acid



Patented Dec. 25, 1951 UNITED- STATES Y'VPATENT.

other: Y

MINERALIOILCONTAINING REsI IErEn ESTERS or SALICYLIC ACID Lnuis A. Mikeska, Westfield, N. J., assignor to. Standard Oil Development Company, a corporation of Delaware No Drawing. Application, Sep ember 3 Serial No. 119,019

This invention relates. to new and useful con.- densation products having pour point depressing characteristics and to a lubricatingv composition containing such material. The invention particularly relates. to a pour point depressant formed by condensing an ester of salicylic acid bricating oil additives, which comprise condensation products of chlorinated ester waxes and is increased by the addition of a mixed calcium salt of an alkyl phenol sulfide'and an alkyl ester of salicylic acid. U. S. Patent 2,373,286, teaches a reaction product of a phosphorus pentahalide with salicylic acid improves a lubricating oil blend by reducing corrosion. 2,458,527, teaches the use of an aldehyde-polyamine-hydroxy aromatic carboxylic acid condensation product as an all purpose additive, especially as a pour depressant.

It has now been found and forms the subject of this invention that a long chain ester of salicylic acid may be condensed with a resinifying agent such as formaldehyde, or a formaldehyde derivative, to yield a condensation product which has exceptional qualities as a pour depressing additive.

The ester of salicylic acid is formed by reacting with the acid a straight chain alcohol or a mixture of alcohols containing from 8 to 24 carbon atoms per molecule. Although any of the alcohols included above are operable it is preferred to use alcohols having a carbon chain length of from to 16, lauryl alcohol being especially preferred.

The esters of salicylic acid obtained by the esterification of the acid are then condensed with a resinifying agent. Operable among the common resinifying agents are, in general, the aldehydes, and, in particular, formaldehyde or its U. s. Patent derivatives such as paraformaldehyde, trloxane, hexamethylenetetramine. and the like. ,In'the condensation reaction exemplifying this inven.-

tion and its preferred embodiment, a mixture of chloromethyl ethyl ether and stannic chloride is used to form the formaldehyde in situ.

To describe the condensation reaction general- 7 ly the ingredients in equimolar proportions are mixed and heated with stirring at a temperature from. about -200 C. The reaction is continued for a time varying between 4-10 hours. The preferred temperature is from 100-150 C., and the time preferred is from about 2 to about 7 hours. It is to be understood of course that the temperatures; and timesused will depend upon the molecular weight of the product it is desired to. obtain. The molecular weight will vary proportionally with the time and temperature of the reaction, and with the relative amounts of the reactants used.

If it is desired the salicylic acid esters may first be condensed with sulfur monochloride or sulfur dichloride, which condensation may then be followed-by the resinifyin reaction with the formaldehyde. The condensates in this case are efiectii'e not only as pour point depressants'but also as anti-oxidants. Metal salts of the condensate such as the barium, calcium, manganese, strontium, aluminum, magnesium, salts, etc., are also eliective as lube oil detergent additives.

The invention will be more clearly explained by a consideration of the following example.

EXAMPLE A three-way flask equipped with a thermometer and a return condenser was charged with 61.2 grams (0.2 mols) of lauryl salicylate and 18.9 grams (0.2 mols) of chloromethyl ethyl ether. To this was then added 5 grams of stannic chloride, whereupon the mixture was heated with stirrin at 85 C. for one and one half hours. At this point a water trap was inserted between the condenser and the reactor and the temperature was gradually raised to C. 8 cc. of a distillate, which collected in the water trap, was removed.

A qualitative test at this point seemed to indicate that the condensation had not gone far enough. Hence, another 18.9 grams of chloromethyl ethyl ether were added and the mixture Was refluxed for 5 additional hours. The temperature gradually rose from 90 to 'C. The reaction mixture thickened considerably during this heating.

The product was then poured into water, acidi- TABLE A. S. T. M. pour point test data A. S. T. M. Pour Point Per cent by weight of additive Oil A 1 Oil B 1 +30 +20 F. 15 (not run.) -20 l5 F. -35 (not run.)

Oil A=A conventionally refind Mid-Continent Neutral of SAE grade having a viscosity at 210 F. of 43.9 S. U. S. and a viscosity index of 101.

1 Oil B A conventionally refined Mid-Continent Neutral of SAE 30 grade having a viscosity at 210 F. of 63.7 S. U. S. and a viscosity index of 86.

(In pour stability tests blend in A 011, the blend remained fluid at -20F., which means that it had excellent pour stability.)

An examination of the data in the table above shows that the product of this invention was effective as a pour depressant in both low and high viscosity oils. The addition of the condensate lowered the pour point of the low viscosity oil from +30 F. to -35 F. in a 1% concentration and the high viscosity oil from +20 F. to F. in a /2% concentration.

Although the pour point characteristics of the condensate of this invention are demonstrated herein by its addition to a mineral base lubricating oil, it is to be understood that this additive is completely compatible with other types of lubricating oils whether a naturally occurring mineral base type or a synthetic type oil.

The material of this invention may be used in bricating oil base stock having combined there conjunction with other lubricating oil additives such as corrosion inhibitors, anti-oxidants, detergent additives, other pour depressants, and viscosity index improvers.

What is claimed is:

1. A lubricating oil composition consisting essentially of a major proportion of a mineral lubricating oil base stock having combined therein a minor proportion of a product formed by subjecting the compound having the general formula:

wherein R is a primary straight chained aliphatic hydrocarbon radical containing from 8 to 24 carbon atoms, to a temperature within a range of from about to about 250 C. for a period of time "within a range of from about 2 to about 20 hours in the presence of an equimolar proportion of formaldehyde.

2. A lubricating oil composition consisting essentially of a major proportion of a mineral luin from 0.2 to 5.0 per cent by weight of a compound formed by subjecting equimolar proportions of lauryl salicylate and chloromethyl ethyl ether to a temperature within a range of from about to about 200 C. for a period'of time within a range of from about 5 to about 15 hours in the presence of stannic chloride.

LOUIS A. MIKESKA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,256,442- Reiff Sept. 16, 1941 2,269,186 DAlelio Jan. 6, 1942 2,357,359 Reiff et al. Sept. 5, 1944 2,380,305 Gleason July 10, 1945 2,499,365 De Groote Mar. 7, 1950 

1. A LUBRICATING OIL COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR PROPORTION OF A MINERAL LUBRICATING OIL BASE STOCK HAVING COMBINED THEREIN A MINOR PROPORTION OF A PRODUCT FORMED BY SUBJECTING THE COMPOUND HAVING THE GENERAL FORMULA: 